Memory foam is a cellular based foam, you can see it at this link:
http://www.tempurpedic.com/TempurCMSVB/material/
I think that if this material is made to conform to any surface, that it might not have any problem conforming to piano strings.  I know it comes in different firmnesses, but am not sure if they offer samples of it.  It might be a superior damping material, or it might be useless.
I think it would be an interesting study though,
-- Chris Rawson, C.P.T., R.P.T.
